Conventional aircraft often produce loud, irritating, or otherwise unwanted noises in the passenger compartment of the aircraft. Acoustic treatments are typically used to reduce the noise in the passenger compartment. Such conventional acoustic treatments are typically effective for attenuating high frequency noises and ineffective for attenuating low frequency noises, such as engine tonal noise created by residual fan imbalance at shaft rotational frequencies.
Accordingly, it is desirable to provide an improved acoustic system for attenuating low frequency noises within an aircraft passenger cabin. Furthermore, other desirable features and characteristics will become apparent from the subsequent summary and detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.